v0.4.0: monitoring & backup — scheduler, CPU/temp metrics, healthchecks, restic backups

Phase 2 (Monitoring & Health):
- Central job scheduler replacing ad-hoc goroutines (internal/scheduler)
- CPU usage collector via /proc/stat background sampling (internal/system/cpu_linux.go)
- Temperature reading from /sys/class/thermal + /host/sys (Docker mount)
- Load average from /proc/loadavg
- Healthchecks.io-compatible HTTP pinger (internal/monitor/pinger.go)
- System health checks: disk, memory, CPU, temp, Docker, protected containers (internal/monitor/healthcheck.go)

Phase 3 (Backups):
- Database auto-discovery via docker ps + docker inspect (internal/backup/dbdump.go)
- Database dumping via docker exec (pg_dump / mariadb-dump) with atomic writes
- Restic backup integration with auto-password generation (internal/backup/restic.go)
- Backup orchestrator: DB dumps + restic snapshots + weekly prune (internal/backup/backup.go)
- Manual backup trigger via dashboard button and POST /api/backup/run

Dashboard UI:
- CPU usage bar with load average display
- Temperature with colored indicator dot
- Backup status card with last run time, DB count, repo stats
- "Mentés most" button for manual backup trigger

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

controller/internal/web/templates/dashboard.html

@@ -33,6 +33,29 @@
                 <div class="system-bar-fill system-bar-{{usageColor .SystemInfo.MemPercent}}" style="width:{{printf "%.0f" .SystemInfo.MemPercent}}%"></div>
             </div>
         </div>
+        <div class="system-info-item">
+            <div class="system-info-header">
+                <span class="system-info-label">CPU</span>
+                <span class="system-info-value">{{printf "%.0f" .SystemInfo.CPUPercent}}%</span>
+            </div>
+            <div class="system-bar">
+                <div class="system-bar-fill system-bar-{{usageColor .SystemInfo.CPUPercent}}" style="width:{{printf "%.0f" .SystemInfo.CPUPercent}}%"></div>
+            </div>
+            <div class="system-load-avg">Load: {{fmtLoad .SystemInfo.LoadAvg1}} / {{fmtLoad .SystemInfo.LoadAvg5}} / {{fmtLoad .SystemInfo.LoadAvg15}}</div>
+        </div>
+        {{if .SystemInfo.TemperatureCelsius}}
+        <div class="system-info-item system-info-item-compact">
+            <div class="system-info-header">
+                <span class="system-info-label">Hőmérséklet</span>
+                <span class="system-info-value">
+                    <span class="temp-dot temp-dot-{{tempColor .SystemInfo.TemperatureCelsius}}"></span>
+                    {{fmtTemp .SystemInfo.TemperatureCelsius}}
+                </span>
+            </div>
+        </div>
+        {{end}}
+    </div>
+    <div class="system-info-items" style="margin-top: 1rem;">
         <div class="system-info-item">
             <div class="system-info-header">
                 <span class="system-info-label">SSD tárhely</span>
@@ -57,6 +80,46 @@
 </div>
 {{end}}
 
+{{if .BackupEnabled}}
+<div class="backup-status-card">
+    <h3>Biztonsági mentés</h3>
+    {{if .BackupStatus}}
+        <div class="backup-info-row">
+            <span class="backup-label">Utolsó mentés:</span>
+            <span class="backup-value">
+                {{if .BackupStatus.Success}}
+                    <span class="backup-status-ok">{{.BackupStatus.LastRun.Format "2006-01-02 15:04"}}</span>
+                {{else}}
+                    <span class="backup-status-fail">Sikertelen</span>
+                {{end}}
+            </span>
+        </div>
+    {{else}}
+        <div class="backup-info-row">
+            <span class="backup-label">Utolsó mentés:</span>
+            <span class="backup-value backup-status-none">Még nem futott</span>
+        </div>
+    {{end}}
+    {{if .DBDumpStatus}}
+    <div class="backup-info-row">
+        <span class="backup-label">Adatbázisok:</span>
+        <span class="backup-value">{{len .DBDumpStatus.Results}} mentve</span>
+    </div>
+    {{end}}
+    {{if .BackupStatus}}{{if .BackupStatus.RepoStats}}
+    <div class="backup-info-row">
+        <span class="backup-label">Tároló méret:</span>
+        <span class="backup-value">{{.BackupStatus.RepoStats.TotalSize}} ({{.BackupStatus.RepoStats.SnapshotCount}} pillanatkép)</span>
+    </div>
+    {{end}}{{end}}
+    <div class="backup-actions" style="margin-top: .75rem;">
+        <button class="btn btn-sm btn-primary" onclick="triggerBackup()" id="backup-btn">
+            {{if .BackupRunning}}Mentés folyamatban...{{else}}Mentés most{{end}}
+        </button>
+    </div>
+</div>
+{{end}}
+
 <h3>Alkalmazások állapota</h3>
 
 <div class="stack-list">
@@ -97,5 +160,28 @@
     {{end}}
 </div>
 
+<script>
+function triggerBackup() {
+    const btn = document.getElementById('backup-btn');
+    btn.disabled = true;
+    btn.textContent = 'Mentés indítása...';
+    fetch('/api/backup/run', { method: 'POST' })
+        .then(r => r.json())
+        .then(data => {
+            if (data.ok) {
+                btn.textContent = 'Mentés folyamatban...';
+                btn.classList.add('loading');
+            } else {
+                btn.textContent = data.error || 'Hiba';
+                btn.disabled = false;
+            }
+        })
+        .catch(() => {
+            btn.textContent = 'Hiba';
+            btn.disabled = false;
+        });
+}
+</script>
+
 {{template "layout_end" .}}
 {{end}}